Hi guys. Why do leaf tips dry on my plant and yellow dots appear on the top leaves? They bloom for about ~30 days. I use AN Ph perfect Sensi Coco at 4ml/l. In: ~1500ppm, Out: 1750ppm, 5.7ph. Thanks.
Leaf tips are a sign of nutrient burn. Your feeding to much. The dots are a deficiency showing up from to many nutrients built up in your coco. Flush with PH adjusted water( No nutrients) until the PPM of the out water shows within 100PPM of the water going in. Let it dry before watering again. Drop your nutrients down to 1200 and see if new growth shows signs. Old growth will not recover.
Happy Growing.
In coco your max ppm, ec is 800 ppm 1.6ec for photos, and 600 ppm 1.2ec for autos.your ph should be set between 6.0 and 6.5 for flower time. 6.2 to 6.3 being your best setting